Sherlock Holmes is a fictional private detective created by Sir Arthur Conan Doyle, known for his extraordinary analytical skills, knowledge of chemistry and phrenology, and his use of deductive reasoning and forensic science to solve difficult cases. Holmes is portrayed as a man of intense logic and rationality, with a keen interest in crime and criminal behavior, yet he is not without personal quirks and idiosyncrasies. He is a smoker of pipes and cigars, a fiddle player, and he has a profound appreciation for literature and the arts. Holmes is famous for his unique relationship with Dr. John Watson, his close friend and biographer, and their arch-enemy, the criminal mastermind Professor Moriarty. Holmes is known for his catchphrase, 'Elementary, my dear Watson'—although the exact wording of this phrase does not appear in Doyle's stories.